dateDiff.js

function dateDisplay (milliseconds) {
	var currentTime = Date.now()
  var diff = currentTime - milliseconds
  
  var divisors = [1000, 60, 60, 24]
  var labels = [' milliseconds ago', ' seconds ago', ' minutes ago', ' hours ago', ' days ago']
  
  for(var i=0;i<divisors.length;i++){
  	if (diff/divisors[i] < 1) {
    	return diff/divisors[i] + labels[i]
    } else {
    	diff = diff/divisors[i]
    } 
  }
  
  return diff + labels[i]
}

console.log(dateDisplay(1000000000000))